Progress on this multi-institutional collaborative effort has focused primarily on quantitative morphometric analysis in the brains of behaviorally characterized subjects in relation to estrogen status. In a study currently under review for publication, for example, Hara and colleagues tested whether the synaptic morphology of terminals innervating dendrites of neurons in Area 46 of the prefrontal cortex are altered in relation to ovarian hormone status and the cognitive outcome of aging. Quantification of serial section electron micrographs focused on non-, single-, and multi-synaptic boutons. The overall result was that, whereas aging alone had relatively little effect, menopause was reliably linked to synaptic morphology and these effects were coupled with individual differences in cognitive capacities that are known to require the dorsolateral prefrontal cortex. Overall this project continues to clarify a number of significant issues concerning the modulatory influence of ovarian hormones on normal cognitive aging.